The purpose of this study, the Tanzanian Drug Treatment as HIV/AIDS Prevention Project (D-TAPP) - Reliability and Validity Study, is to conduct formative research necessary to the implement of drug treatment as an HIV prevention intervention in Dar es Salaam, Tanzania. The specific aims of D-TAPP 1) - Reliability and Validity Study are: Aim1: To develop culturally appropriate measures of psychological functioning, social functioning, treatment motivation, addiction severity, and readiness for treatment;Aim 2: To assess IDUs'understanding and relevancy of the measures of psychological functioning, social functioning, treatment motivation, addiction severity, and readiness for treatment;and Aim 3: To test the reliability and validity of the D-TAPP Questionnaire. The D-TAPP - Reliability and Validity Study will be implemented in three components reflecting the three specific aims using a mixed methods design. In component 1, the D-TAPP questionnaire will be translated from English to Swahili and the accuracy of the translations and the content validity of the translated measures will be assessed by a panel of native Swahili-speaking experts. In component 2, semi-structured interview data will be collected from a purposeful sample of 40 IDUs. In this component, the D-TAPP questionnaire will be presented to IDU participants, and they will be asked to assess the understandability and cultural relevancy of each item in the questionnaire (Aim 2). Participants will also be asked to evaluate scales used to record measurement responses. In particular, IDUs will be asked to make recommendations that will improve understandability, cultural relevancy, and response measurement. The questionnaire will be modified to reflect findings produced by the Component 2 study. Component 3 will assess the psychometrics of the measures. Internal and 48 hour test/retest reliability will be determined along with content, construct and criterion related validities. For this study, a purposeful sample of 150 IDUs will be recruited to participate. Data will be collected at intake and 48 hours later. PUBLIC HEALTH RELEVANCE: Tanzanian Drug Treatment as HIV/AIDS Prevention Project (D-TAPP) - Reliability and Validity Study will investigate the psychometric properties of standardized measures of treatment motivation in a sample of Tanzanian injection drug users.